OCN Oncology Certified Nurse (ONS) Practice Test

A 62-year-old patient with metastatic non-small cell lung cancer starts pembrolizumab after tumor testing shows PD-L1 expression of 80% and no actionable EGFR or ALK alteration. Six weeks later the patient reports 8 watery stools per day, cramping, and lightheadedness. The patient asks whether to take loperamide and come for the next infusion. Which nursing response best matches current immune checkpoint inhibitor toxicity management?

During report, a nurse learns that a 45-year-old patient with breast cancer developed sudden chest pain, dyspnea, and hypotension 2 hours after central venous catheter placement. The patient has elevated D-dimer and decreased oxygen saturation. Which oncology emergency should the nurse prioritize in the differential diagnosis?

A 58-year-old patient with newly diagnosed stage III breast cancer is beginning chemotherapy with doxorubicin and cyclophosphamide. Which assessment finding is most important for the nurse to monitor during treatment to detect a potential life-threatening cardiac complication?

A 45-year-old patient receiving active chemotherapy presents to the emergency department with chest pain, dyspnea, and hypotension. The nurse recognizes these as potential signs of malignant pericardial effusion with tamponade. Which pathophysiologic mechanism best explains the hemodynamic compromise in this oncology emergency?

During chemotherapy administration, a patient develops sudden onset flushing, urticaria, bronchospasm, and tachycardia within 5 minutes of infusion initiation. Vital signs show BP 92/58 mmHg, HR 118 bpm. The patient received the same agent 3 weeks prior without incident. In analyzing this clinical presentation, which mechanism best explains the pathophysiology of this reaction?